Vehicle spring



\ y provision of a useful Improvements in Vehicle Patented Dec. 2, 1924.

PERRY B. NEWKIRK, 0F. SEATTLE, WASHINGTON.

VEHICLE SPRING.

y Appllcation filed November 24, 1922. Serial No. 603,109.

To @ZZ @Li/0m t may concern:

Be it known that I, PERRY B. Newman, a citizen of the United States, residing at Seattle, in the county of King and State of lVashington, have invented certain-new and Springs, of which the following is a specification.

My invention relates to improvements in vehicle springs of the multi-leaf semi-elliptic type, and has for its main purpose the spring of this type wherein the spring will yield more readily to loading up to a certain point,y which may be termed the maximum normal load point, thanv it will to greater loads.

The mechanical principle involved is that of shortening the moment arms of the spring and this shortening' of these arms is brought about7 in elfect, by the construction of the spring itself and not in external stops or yfulcra against which the spring may bear when heavily loaded.

A vehicle provided with springs embodying my invention will be found to ride easily and comfortably under all conditions of loadingsince the spring will flex readily under light loads while they `will automatcally stiften up and become less flexible under heavy loads.

In the following description7 I shall refer tothe following drawings, in which Fig. 1 is a side elevation vof a spring with an axle mounting therefor as it appears under unloaded conditions.

F ig'. 2 is a view similar to Fig. 1, but

showing the spring in the position assumed under maximum normal or light load conditions.

Fig. 3 is a view similar to Figures 1 and 2, but showing the appearance of the spring under heavy loading.

Fig. 4 is an enlarged view of the central or axle supported part of my spring with the leaves shown in unloaded condition in full lines and in loaded condition in dotted lines.

Fig. 5 is a section on the line 5 5 of Figure 4, the dotted line portion being omitted.

The spring seat used for the center of this spring is here shown as consisting of a central or body portion 10 of hollow cylindrical form so that it may surround the axle 11. From this body portion extend the anti-clinally arranged wings 12. Thus between the wings the upper part of the body til the maximum light load is forming the center of the segmento-cylindrical.

provided with jopeningsthe threaded ends 13 of The wings 12 are for the reception of the spring clips 14 which are held in position by the usual nuts.V l5

spring seat isy vThe spring itself consists of'a series of leaves, each having an upwardly bowed central portion 16 and normally straight end portions 17 connected to the central portion by portions 18 curved reversely to thev central portion. The reverselyr curved portions are held beneath thef spring leaves aregraduated in length, the4 upper leaf beingthe longest and each succeeding leaf being shorter thanthe one above it. The Lipper erably provided with the usual eye 20 for the reception of the ordinary spring shackle bolts (not shown).

In use my spring' under unloaded condition appears as in Fig. 1 with the bowed central portions vertically spaced and the leaf ends straight and inclined upwardly from the center toward the-ends sothat they are synclinally arranged. As Lload is applied to the spring the ends beyond the clips swing downwardly but remain straight unreached. Under such conditions of light loading the central bowed portions gradually approach each other until the maximum light load is reached at which time they will be in contact and the spring will appear as in Fig. 2. Up to this point the moment arm of each half of the spring will be substantially half the distance between the extremities of the longest leaf. Until the point is reached at which the central bowed portions are in contact the lengths of these moment arms will not vary appreciably but when this point is reached the condition of the center of the spring becomes the same as if it were rigid, and all further flexure takes place beyond the spring clips so that the moment arms are, in effect, shortened and further loading causes the spring ends to assume a position oppositely disposed iat they are concentric to each other. Thev bowed centers are ec or longest leaf is pref- I have described in detail the particular `construction illustrated in the accompany ing drawings for the purpose of clearly disclosing an embodiment of my invention, but it will be evident to those skilled in the art that various changes and modifica- -"tions may be made without departing from my invention.

I claim:

l. A vehicle spring including a series of leaves arranged one above the other and having their central portions spaced one from the other under unloaded conditions and their ends contacting throughout on each side of said central portions.

2. A vehicle spring including a series of leaves each having an upwardly bowed central portion and oppositely directed end portions, said central portions being ,arranged to provide gaps between adjacent leaves under unloaded and lightly loaded conditions, said end portions contacting throughout their lengths, and clips binding the leaves together on each side of the cen tral portions,

3. A vehicle spring including a series of leaves each having an upwardly bowed central portion and synclinally arranged end portions, said upwardly bowed portions under unloaded and lightly loaded conditions being all of substantially the same radius and eccentrically arranged to provide gaps between adjacent central portions, said end portions being in contact throughout their lengths, and means for clamping the leaves together at each side of the central por tions.

4. A vehicle spring including a series of leaves each having an upwardly bowed central portion and synclinally arranged end portions connected to the central portion by intermediate portions curved reversely to the central portion, said upwardly bowed portions under unloaded and lightly loaded conditions being all of substantially the same radius and eccentrically disposed whereby to provide gaps between adjacent central portions under said conditions, said reversely curved portions contacting with each other in concentric arrangement, the end portions being in contact throughout, and means to clamp the reversely curved portions of the leaves together.

5. A vehicle spring including a series of leaves each having an upwardly bowed central portion and synclinally arranged end portions connected to the central portion by intermediate portions curved reversely to the central portion, said upwardly bowed portions under unloaded and lightly loaded conditions being all of substantially the same radius and eccentrically disposed whereby to provide gaps between adjacent central portions under said conditions, said reversely curved portions contacting with each other in concentric arrangement, the end portions being in contact throughout, a spring seat comprising an upwardly bowed segmento-cylindrical central portion beneath the central leaf portions, and anticlinal wings extending from the central portion beneath the reversely curved leaf portions, and spring clips binding the reversely curved leaf portions together and to said wings.

In testimony whereof I affix my signaf ture.

PERRY B. NEWKIRK. 

